1. Field of the Invention
The present invention relates to a magnetic head suspension for supporting a magnetic head slider that reads and/or writes data from and to a recording medium such as a hard disk drive.
2. Related Art
A magnetic head suspension that supports a magnetic head slider is required to accurately position the magnetic head slide to a center of a target track.
More specifically, the magnetic head suspension is directly or indirectly connected at a proximal side to an actuator such as a voice coil motor, and positions the magnetic head slider, which it supports at a distal side, to the center of the target track by being swung around a swing center by the actuator.
By the way, if the magnetic head suspension resonates at the time when being swung around the swing center, the magnetic head slider is largely displaced from the target track. In particular, out of the various vibration modes possibly generated in the magnetic head suspension, the first bending mode and the first torsion mode have the resonance frequencies within the low frequency range. It is therefore required to prevent or reduce the displacement of the magnetic head slider due to the vibrations of the first bending mode and the first torsion mode.
For example, there is proposed a magnetic head suspension with a load beam part that has a plate-like main body portion facing a disk surface and paired flange portions extending respectively from side edges of the main body portion in a direction away from the disk surface (see Japanese Unexamined Patent Publication Nos. 2005-032393, 2008-021374 and 2009-295261, which are hereinafter referred to as prior art documents 1-3).
Each of the magnetic head suspensions disclosed by the prior art documents 1-3 enhances the rigidity of the load beam part thanks to the paired flange portions, thereby increasing the resonant frequencies of the first torsion mode and the first bending mode to prevent occurrence of the resonant vibrations of the first torsion mode and the first bending mode as much as possible.
Furthermore, the prior art document 3 discloses that a displacement amount of the magnetic head slider in the seek direction at the time when the magnetic head suspension is vibrated can be adjusted by bending the load beam part with the paired flange portions at two positions including a proximal-side bending line and a distal-side bending line, both of which are along a suspension width direction.
However, in the magnetic head suspension disclosed by the prior art document 3, a bending direction at the proximal-side bending line and a bending direction at the distal-side bending line are different from each other. More specifically, the load beam part is bent in such a convex manner as to project in a direction away from the disk surface at one of the proximal-side bending line and the distal-side bending line, while the load beam part is bent in such a convex manner as to project in a direction toward the disk surface at the other one of the proximal-side bending line and the distal-side bending line.
Since the bending directions of the load beam part at the proximal-side bending line and the distal-side bending line are different from each other as explained above, there is a problem that a bending process of the load beam part is made difficult.
In particular, the paired flange portions are bent in the direction away from the disk surface as explained above. In a case where the load beam part with such flange portions is bent in such a convex manner as to project in the direction away from the disk surface at the bending line along the suspension width direction, there is also a problem that the flange portions are likely to be deformed.
Further, the prior art documents do not disclose a configuration for simultaneously minimizing both a displacement amount of the magnetic head slider due to the vibration of the first torsion mode and a displacement amount of the magnetic head slider due to the vibration of the first bending mode.